<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title>Page Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>

<body>
    <div id="todo-list-example">
        <form v-on:submit.prevent="addNewTodo">
            <label for="new-todo">Add a todo</label>
            <input v-model="newTodoText" id="new-todo" placeholder="E.g. Feed the cat">
            <button>Add</button>
        </form>
        <ul>
            <li is="todo-item" v-for="(todo, index) in todos" v-bind:key="todo.id" v-bind:title="todo.title" v-on:remove="todos.splice(index, 1)"></li>
        </ul>
    </div>
</body>
<script>
    Vue.component('todo-item', {
        template: '\
    <li>\
      {{ title }}\
      <button v-on:click="$emit(\'remove\')">Remove</button>\
    </li>\
  ',
        props: ['title']
    })

    new Vue({
        el: '#todo-list-example',
        data: {
            newTodoText: '',
            todos: [{
                id: 1,
                title: 'Do the dishes',
            }, {
                id: 2,
                title: 'Take out the trash',
            }, {
                id: 3,
                title: 'Mow the lawn'
            }],
            nextTodoId: 4
        },
        methods: {
            addNewTodo: function() {
                this.todos.push({
                    id: this.nextTodoId++,
                    title: this.newTodoText
                })
                this.newTodoText = ''
            }
        }
    })
</script>

</html>